1. Field of the Invention
This invention relates to internal combustion engines and in particular to an apparatus for preheating air delivered to a cold engine.
2. Description of the Related Art
The problem of starting an internal combustion engine in cold weather conditions is well known. Various attempts to solve the problem have met with limited success. Most approaches to the problem have involved using some type of burner device to increase the air temperature within the cylinders to move that temperature into the range needed for combustion. The problem is particularly acute with diesel engines in which combustion in the cylinders is induced by the heat produced by compression of the air-fuel mixture.
For example, U.S. Pat. Nos. 3,526,214 and 3,687,122 to Kamo disclose a combustion aid for compression ignition engines. These complicated combustion aids includes a fuel burner for burning engine fuel located in the air intake of the engine and a distributing means mounted within the air intake for distributing the hot gases that are generated from the products of combustion. Significant engine modification is needed to use the Kamo devices.
Similarly, U.S. Pat. No. 3,630,183 to Hoffman shows a complex diesel engine manifold air preheater. The Hoffman device includes an elongated burner tube mounted in and running lengthwise along the manifold and a burner head assembly which includes a spark plug and fuel nozzle for preheating the air to the manifold.
U.S. Pat. No. 3,765,389 to Henchel discloses yet another burner type heater apparatus with controlled air and fuel intake. This engine preheater apparatus comprises an air delivery system, burner apparatus, chimney heat exchanger apparatus, coolant jacket apparatus, and a fuel system. Another air intake preheater involving the burning of diesel fuel is disclosed in U.S. Pat. No. 3,977,376 to Reed, et al. The Reed preheater includes a metering and control system for supplying fuel to a burner nozzle of a burner assembly which preheats intake air in a diesel engine. Another diesel burning preheater and control system is disclosed in U.S. Pat. Nos. 4,099,488 and 4,192,274 to Damon. The Damon systems involves heating the engine coolant and using the heated coolant to heat the engine block. U.S. Pat. No. 4,706,644 to Nakai involves a two-stage heat exchanger, blower, coolant pump, and fuel pump that work in combination to heat the engine coolant in the heat exchanger.
U.S. Pat. No. 4,744,747 to Kawamura, et al., discloses a heater controller. The Kawamura device includes an atomizing glow plug for atomizing fuel and an ignition glow plug for igniting the atomized fuel. U.S. Pat. No. 5,003,941 to Jeoffrey, Jr., et al., discloses a gas fired system involving a heat exchange for heating engine coolant.
Implementing any one of these systems involves significant design changes to the engine which makes them unsuitable for a retrofit of an existing engine. It would therefore be desirable to have a simple device that would provide additional heat for combustion in cold weather conditions that can be used on virtually any internal combustion engine.